The primary goal of this program is the development of L.E.A.P.S.(TM) heteroconjugate peptide vaccines against herpes simplex virus) to prevent or treat human infection. The heteroconjugate vaccines are constructed of peptides which contain defined T cell epitopes and peptides which are predicted to bind to T cells or antigen presenting cells. The T cell epitopes that are being used are from the ICP27, glycoprotein B, and glycoprotein D of HSV-1. Our Phase I studies proved the principle behind this new technology by showing that incorporation of a viral peptide epitope into a L.E.A.P.S. construct based vaccine can enhance and define the type of immune response which is elicited to promote the development of protective and not detrimental immune responses. A L.E.A.P.S. vaccine can then be formulation with LEAPS constructs assembled with adjuvants to produce defined immune responses to defined epitopes. The major goal of the Phase II studies will be to optimize the vaccine formulation with respect to L.E.A.P.S. peptide (or mixture), the adjuvant and other components to allow progression to human trials. In addition, we will study the mechanism of action by which the L.E.A.P.S. peptide potentiates the immune response. The HSV vaccines are also prototypes for the development of heteroconjugate vaccine to treat or prevent disease caused by other infectious agents. The ultimate goal of our study will be to develop sufficient data to allow progression to human trials. PROPOSED COMMERCIAL APPLICATION: Heteroconjugate peptide vaccines use proprietary new technology called L.E.A.P.S. (Ligand Epitope Antigen Presentation System) to provide treatment and/or prophlysis against herpes simplex virus (HSV) infection and disease. HSV is a common oral pathogen and sexually transmitted disease which also causes serious disease. An estimated 40 to 60 million Americans are infected with HSV with approximately 600,000 new cases occurring per year. The HSV vaccine will be prototypes for the development of heteroconjugate vaccines to treat or prevent disease by other infectious agents.